Blanks, or work pieces, are treated while moving on a conveyor past an applicator. For example, glue is applied to a carton blank as it moves on a conveyor passed a glue applicator.
To set the applicator to apply the treatment at the desired location, an operator measures the desired location and sets the applicator. This procedure has potential for error, as the operator may incorrectly measure the desired location, or incorrectly set the applicator.
Further, once set, the applicator may apply the treatment in a location other than the desired location due to changes in operating conditions. For example, where the applicator is a glue applicator, glue valve delay, or changes in glue pressure or consistency may cause the glue to be applied to the blank at a location other than the desired location. The operator must measure the applied location of the treatment, and reset the applicator until the applied location matches the desired location. This is a time consuming process as it requires several repetitions, thereby reducing productivity.
Additionally, operation of the applicator results in wear, necessitating that parts of the applicator be replaced. For example, where the applicator is ,a glue applicator including a glue valve, operation of the glue applicator causes wear to the glue applicator valve. To sense applicator component wear, the operator monitors the applicator by observing an applied location of the treatment. A difference between the applied location and the desired location greater than a predetermined value indicates the worn components, necessitating replacement of the worn components. Due to error in the operator's observations, applicator components are often not replaced at the correct time.